1. Field of the Invention
The present invention relates to an electric vehicle in which each drive wheel is independently driven by its own (dedicated) electric motor.
2. Prior Art
Vehicles which use electric motors to drive the wheels are known in the prior art. A single electric motor is conventionally used to drive only the front wheels or only the rear wheels. In another prior art approach, two electric motors are employed to drive the front wheels and the rear wheels, respectively.
Generally in an electrically-driven vehicle, when energy is fed back into the power system, the motors are regeneratively braked. In the prior art electric vehicle, a single motor drives two wheels and so it is inevitable that the same regenerative braking force is applied to the left and right drive wheels driven by the motor. This has posed problems. In particular, when the brakes are hit, or when the brakes are applied while the vehicle is making a turn, unequal loads are applied to the wheels. That is, a heavy load is applied to one wheel, while very light loads are applied to the other wheels. In this way, when the loads applied to the left and right wheels differ, i.e. when the forces with which the wheels are pressed against the road differ, if the same braking force is applied to the left and right wheels, then the lightly loaded wheel tends to easily lock. This makes it difficult to ensure that the vehicle continues stable travel.